This application is a U.S. national stage application of PCT application PCT/JP2009-059808, filed May 28, 2009, and claims the benefit of priority from Japanese patent application 2008-140739, filed May 29, 2008.
1. Field of the Invention
The present invention relates to a network boot system which boots an operation system over a network.
2. Description of the Related Art
A system (hereinafter referred to as a “network boot system”) which boots an operating system (hereinafter referred to as an “OS”) over a network has received attention in recent years. The system is composed of at least one network boot server (I/O server) and a plurality of client terminals connected over a network. Several types of system configurations are available as candidates for the system. The most common one is such that all programs and data such as an OS and application software operating on a client terminal are stored as image data (virtual disk) in a storage device (e.g., a hard disk) on the server side and such that the OS is loaded onto the client terminal over a network when the client terminal is booted.
Japanese Patent Laid-Open No. 2007-323354 discloses a network boot system in which a virtual machine is utilized for a PC (client terminal) that is used by an end user.
In the network boot system, a network boot server which provides an operating system operating on a client terminal and a client terminal are connected to each other over a network, the client terminal includes a physical memory which can temporarily store at least data necessary during boot-up of the operating system and a network interface for accessing the server over the network, and the operating system includes a network driver for driving the network interface and a filter driver for converting access to a local bus of the client terminal into access to the network.
If a network boot system has a mechanism in which a plurality of client terminals share a disk image including OS over the network, each client terminal may be diskless, i.e., need not have a hard disk. The network boot system has the advantage of being able to manage all data including an OS of each client terminal in a centralized manner on the server side. The network boot system is thus suitable for a system in which a large number of client terminals operate.
Since an OS and application software are executed using a CPU and a physical memory of each client terminal, the network boot system also has the advantage of being able to maximize the performance of each client terminal and minimize server loads.